Review Article Integrative Food, Nutrition and Metabolism Integr Food Nutr Metab, 2020 doi: 10.15761/IFNM.1000293 Volume 7: 1-11 ISSN: 2056-8339 Crosstalk between food components and microRNAs: Role in metabolism, nutrition, health and diseases Simardeep Kaur and Suresh Kumar* Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India Introduction Understanding the response of the human body to dietary components and other environmental factors unravels the roles of the environment on gene expression, and presents the opportunities to modulate metabolism, health, and diseases based on nutrition. Foods are known to provide a conditioning environment to shape the activity of the genome and physiology of the body [1]. A better understanding of the infuence of nutrients on gene expression might help to manage a healthy life. Te role of the environment in modulating gene expression comes through epigenetic changes, and if epigenetics is contemplated as a harmonizing process, many of the phenotypic variations can be easily explained [2]. Epigenetic variations (total of all the changes in genetic material without altering the underlying nucleotide sequence) including modifcations in chromatin architecture, histone protein, DNA methylation, and non-coding RNA biogenesis afect gene expression [3]. Non-coding RNAs play a very important role in epigenetic modifcations and gene regulation. More importantly, some of the epigenetic changes may be inherited to the next generation that might result in phenotypic variations [4]. It is becoming apparent that changes in the epigenome of living organisms play a crucial role in tolerance to environmental stresses, nutrient availability, and evolution processes [5]. Research on nutriepigenomics justifes the direct association between dietary nutrients and epigenetic variations. Epigenetic changes are gaining exceptional importance because of the ability of bioactive food components to afect the epigenetic status of gene/genome [6]. Bioactive food components can alter the epigenetic pattern via their availability. Nutrients like folic acid, vitamin-B 12 , methionine, and choline afect the epigenetic modifcations through one-carbon metabolism [7]. Certain bioactive food components afect S-adenosylmethionine (AdoMet) or S-adenosylhomocysteine (AdoHcy) level in the tissue which alter methylation of DNA/histone proteins [8]. *Correspondence to: Suresh Kumar, USDA Norman E. Borlaug Fellow, IUSSTF Fellow, Principal Scientist, Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi-110012, India. Tel: +91 11 25842038; Fax: +91 11 2584 6420; E-mail: sureshkumar3_in@yahoo.co.uk; sureshkumar@iari.res.in Key words: dietary component, microRNA, nutrition, polyphenols, vitamin, fatty acid, mineral, cardiovascular disease, infammation, cancer, obesity Received: September 17, 2020; Accepted: October 26, 2020; Published: October 30, 2020 Abstract Human health is signifcantly afected by dietary patten, nutritional habits, quality of food, and lifestyle. Te diets enriched with bioactive food components like polyphenols, vitamins, minerals, polyunsaturated fatty acids, butyrate, and other dietary fbers are generally associated with a lesser incidence of chronic diseases such as cancer, cardiovascular disorders, and obesity. Apart from being antioxidants, some of these bioactive dietary components have the potential to regulate several cellular signaling pathways, modulate gene expression, afect transcription factors, and alter the microRNAs profle. MicroRNA (miRNA) is a non-coding-RNA that regulates the expression of its target gene(s) through its catalytic/regulatory functions. Te miRNA is generally synthesized endogenously but it can also be obtained through dietary components that can change the expression of other genes. miRNA targets the specifc mRNA, modulates expression of the gene(s) via binding to its complementary regions; thus, down-regulates the expression of the genes. Dietary food components impact cellular diferentiation processes, proliferatory pathways, and pathophysiological conditions; thus, have the potential to afect the activity of genes associated with chronic diseases including cancer, cardiovascular diseases, and obesity by modulating the associated signaling pathways. Tis review discusses the role of dietary food components like polyphenols (quercetin, resveratrol, curcumin, α-mangosteen, and epigallocatechin gallate), vitamins (A, D, and folic acid), Omega-3 polyunsaturated fatty acids, butyrate, and minerals (selenium, zinc) in modulating miRNA expression and their potential in causing chronic diseases. Decades ago, it was postulated that mRNA is a messenger and key player in the central dogma of molecular biology, as it connects a gene to a functional protein. However, subsequent studies led to the discovery of certain other unique RNAs that play a vital role in gene expression and regulation, but do not code for a protein; hence, termed non-coding RNAs (ncRNAs). One of the most common examples of ncRNAs is microRNAs (miRNAs). MicroRNAs are short (generally 22 nucleotides) in length, and the majority of them are involved in the down-regulation of gene expression at the post-transcriptional level [9,10]. In the majority of the cases, miRNA silences the gene expression via interacting with mRNA based on the complementarity between the bases of miRNA and mRNA, generally target at the 3′ UTR region. Tis constitutes another way for gene regulation in living organisms including plants and mammals. Such a method of regulation of gene expression helps to fne-tune the expression of genes under varying environmental conditions. Within a decade, hundreds of miRNAs have been discovered in both plant and animal systems which possess highly conserved sequences and play important roles in the cell, tissue, and organ development, physiology as well as phenotype of the individual. Tus, miRNAs play important roles in regulating the expression of genes that in turn afect a variety of metabolic processes in an individual [11].